ISSUE FOCUS 32 FEED & ADDITIVE MAGAZINE March 2024 of mycotoxins with the toxin binder is dependent on the polarity of the toxin and the surface charge of the clay. In an acidic environment, there is a higher surface charge and thus adsorption of mycotoxins is highest in the gastric stomach of the animal. At intestinal pH, which is closer to neutral, the negative charge disappears and there is a risk of releasing the toxin from the clay surface, namely desorption. The release is thus dependent on the strength and stability of the binding. Polarity is an important factor, but the structure and molecular size of the toxin is also of importance. For example, aflatoxins are polar, small and 2-D in structure. Therefore, they have a high binding percentage as aflatoxins fit between the layers of clay minerals. In contrast, fumonisins are polar and very big in molecular size. This implies that the binding site is limited towards the exterior of the clay mineral and not in between the layered sheets. Hereby fumonisins show more desorption as the molecule is not trapped by the binder (figure 1). Furthermore, it is possible to enhance the binding efficiency of less polar mycotoxins by modifying the clay’s surface. In addition, research has shown that clay minerals could bind LPS (figure 1). However, gram-negative bacteria in the intestine reside close to the epithelial barrier and hence the contact time between LPS and the clay mineral might not be sufficient to prevent epithelial damage. For this reason, it is more important to lower pathogenic counts in the gut microbiome instead of combatting their endotoxins with toxin binders. As toxin binders have limitations, effective anti-mycotoxin solutions should be based on supporting the animal’s health by preventing damage to organs, the gut barrier and modulating the immune system. In that way, it is not important which mycotoxin is ingested by the animal. When the gut barrier and liver are functioning properly, the animal’s immunity and performance can simply not be compromised by the toxin. Therefore, Impextraco believes that effective mycotoxin solutions should be evaluated on real animal trials (in vivo trials), and more specifically on research on the immune status and gut health in the presence of a specific mycotoxin challenge. With the aid of biomarkers, many gut, organ and immune parameters can be evaluated nowadays. IN VIVO RESULTS Our solution, Elitox®, was evaluated in vivo during a fumonisin contamination. In total 480 Cobb® male broilers were raised until 39 days of age. The chicks were divided over 24 pens so that the average initial body weight in each pen was identical at the start of the trial. The animals were fed ad libitum with a starter, a grower and a finisher feed between day 1-14, day 15-32, day 33-39, respectively. There were 3 treatments and 8 replicates per treatment. The first group received a basal corn-soybean meal diet, while the second group received the same diet which was contaminated with 100 ppm fumonisins in the grower phase from day 21-28. The third group received the contaminated diet supplemented with Elitox® at a 2 kg/T inclusion rate. The aim of the trial was to evaluate the impact of a severe and acute fumonisin contamination on the immunity of the broilers using flow cytometry measurements. Per treatment, 8 blood samples were collected and analyzed. Flow cytometry detects and quantifies the proportion of different subsets of immune cells based on cell membrane markers, i.e. the presence or absence of CD4 and CD8 receptors. As such you receive a picture of the immune status of the bird, which allows to detect changes in immune response. In the following results, the impact of fumonisin contamination on the bird’s immune response is demonstrated. On day 28, directly after the acute exposure to fumonisins, a clear impact on immune cells was noticed. In the contaminated group, the total pool of different subsets of immune cells was clearly lowered indicating immunosuppression (figure 2). This can be explained by the toxic effects of fumonisins towards circulating immune cells. In fact, fumonisins resemble cell membrane components and hence interfere with the building blocks of membranes of immune cells. Hereby different immune cells are targeted and destroyed by the toxin. Nevertheless, Elitox® prevented this reduction in immune cells and thus protected the birds from the negative effects of fumonisins. As we have shown in figure 1 that commonly used clay minerals are limited in fumonisins binding, immune supporting agents are
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